﻿//
// System.ComponentModel.Design.Serialization.InstanceDescriptor.cs
//
// Authors:
//   Martin Willemoes Hansen (mwh@sysrq.dk)
//   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
//
// (C) 2003 Martin Willemoes Hansen
// (C) 2003 Andreas Nahr
// Copyright (C) 2005 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.Collections;
using System.Reflection;
using System.Security.Permissions;

namespace System.ComponentModel.Design.Serialization
{
    //[PermissionSet(SecurityAction.LinkDemand, Unrestricted = true)]
    public sealed class InstanceDescriptor
    {

        private MemberInfo member;
        private ICollection arguments;
        private bool isComplete;

        public InstanceDescriptor(MemberInfo member, ICollection arguments)
            : this(member, arguments, true)
        {
        }

        public InstanceDescriptor(MemberInfo member, ICollection arguments, bool isComplete)
        {
            this.isComplete = isComplete;
            ValidateMember(member, arguments);
            this.member = member;
            this.arguments = arguments;
        }

        private void ValidateMember(MemberInfo member, ICollection arguments)
        {
            if (member == null)
                return;

            switch (member.MemberType)
            {
                // According to docs only these types are allowed, but the docs do
                // state what happens for other types
                case MemberTypes.Constructor:
                    ConstructorInfo CI = (ConstructorInfo)member;
                    if (arguments == null) // null counts as no arguments
                        if (CI.GetParameters().Length != 0)
                            throw new ArgumentException("Invalid number of arguments for this constructor");
                    if (arguments.Count != CI.GetParameters().Length)
                        throw new ArgumentException("Invalid number of arguments for this constructor");
                    break;
                case MemberTypes.Method:
                    MethodInfo MI = (MethodInfo)member;
                    if (!MI.IsStatic)
                        throw new ArgumentException("InstanceDescriptor only describes static (VB.Net: shared) members", "member");
                    if (arguments == null) // null counts as no arguments
                        if (MI.GetParameters().Length != 0)
                            throw new ArgumentException("Invalid number of arguments for this method", "arguments");
                    if (arguments.Count != MI.GetParameters().Length)
                        throw new ArgumentException("Invalid number of arguments for this method");
                    break;
                case MemberTypes.Field:
                    FieldInfo FI = (FieldInfo)member;
                    if (!FI.IsStatic)
                        throw new ArgumentException("Parameter must be static");
                    if (arguments != null && arguments.Count != 0) // null counts as no arguments
                        throw new ArgumentException("Field members do not take any arguments");
                    break;
                case MemberTypes.Property:
                    PropertyInfo PI = (PropertyInfo)member;
                    if (!(PI.CanRead))
                        throw new ArgumentException("Parameter must be readable");
                    MethodInfo PIM = PI.GetGetMethod();
                    if (!PIM.IsStatic)
                        throw new ArgumentException("Parameter must be static");
                    break;
            }
        }

        public ICollection Arguments
        {
            get
            {
                // It seems MS does not return null even if we specified null as parameter (but does not cause an exception)
                if (arguments == null)
                    return new object[0];
                return arguments;
            }
        }

        public bool IsComplete
        {
            get { return isComplete; }
        }

        public MemberInfo MemberInfo
        {
            get { return member; }
        }

        public object Invoke()
        {
            if (member == null)
                return null;

            object[] parsearguments;
            if (arguments == null)
                parsearguments = new object[0];
            else
            {
                parsearguments = new object[arguments.Count];
                arguments.CopyTo(parsearguments, 0);
            }

            //MemberInfo member;
            switch (member.MemberType)
            {
                case MemberTypes.Constructor:
                    ConstructorInfo CI = (ConstructorInfo)member;
                    return CI.Invoke(parsearguments);

                case MemberTypes.Method:
                    MethodInfo MI = (MethodInfo)member;
                    return MI.Invoke(null, parsearguments);

                case MemberTypes.Field:
                    FieldInfo FI = (FieldInfo)member;
                    return FI.GetValue(null);

                case MemberTypes.Property:
                    PropertyInfo PI = (PropertyInfo)member;
                    return PI.GetValue(null, parsearguments);
            }
            return null;
        }
    }
}